Linear-pivotal converter

ABSTRACT

A device for converting reversible linear motion to reversible pivotal motion wherein the member undergoing pivotal motion is locked against motion at both limits thereof.

United States Patent 11 1 Harvey et 81.

[ Aug. 14, 1973 LINEAR-PIVOTAL CONVERTER 2,645,882 7/1953 Cook 46/77 2,896,369 7/1959 Palensky 46/76 R [76] I Invent: William Harvey 3,132,829 5/1964 Bochman, 11...; 244/102 R y P 202, Roqkvllle, d- 2,763,348 9/1956 Corbin 61 a]. 46/77 x 20850; Robert S. Violett, 64B, Rt. No. l, Clarksburg, Md. 20734 P E Ml B m rimary xamineri ton uc er [22] led: May 1972 Assistant Examiner-Paul E. Sauberer [21] App], No,; 257,500 Attorney-Raymond N. Matson [52] US. Cl. 244/102 SL, 46/77, 74/99 R 511 1111. q. B64c 25/26 [57] ABSTRACT [58] Field of Search. 74/99 R; 46/74, 76, A device for converfin g revers1ble lmear motlon to re- 46/77 244/102 100 R versible pivotal motion wherein the member "undergo- I References Cited 223! r-not1on 1s locked agamst mouon at both 11m- I UNITED STATES PATENTS 2,444,319 6/1948, Wimer 244/102 s1. 10 Claims, 7 Drawing Figures 20 25 28 44 ,11 24 22 M \L 1'I1..T\ L If i 1 m f I V it] 1 26 +32 14 E 1T; 3- I6 74 K 2 .4 .6 a--- 2 -2 9 9- Y 38 5o 4 36 4o PAIENIEnAm; 14 ms 3; 752421 sum 1 er 2 PATENIEI] MB 14 I973 SHEET 2 [If 2 LINEAR-PIVOTAL CONVERTER This invention relates generally to devices for convetting one type of motion to another and more particularly to a device which will convert reversible linear motion to reversible pivotal motion with the pivotable member being locked at either end of its pivotal movement through a given arc.,

Linear to pivotal converters are known in the art but insofar as is known, are characterized by various inherently disadvantageous features. Among these are a complexity of structure rendering them difficult to manufacture and hence unnecessarily expensive, the use of cables requiring frequent replacement or maintenance, and a lack of reliability in operation.

Accordingly, the main object of the present invention is to provide an improved linear to pivotal motion converter which will obviate the above and other disadvantageous features characterizing known devices.

An important object of the present invention is to provide an improved linear-pivotal motion converter in which the pivotal member is locked in position at each limit of motion.

Another important object of the present invention is to provide an improved linear-pivotal motion converter in which the pivotal member moves through a predetermined arc which is determined by the angle defined by a pair of seating surfaces against which the pivotal member isselectively locked.

A further important object of the present invention is to provide a linear to pivotal motion converter which has a minimum of moving parts, is strong and of long life in use, has many useful applications, and is suscep- ;tible of ready and economic manufacture.

Otherobjects and advantages of the present'invention will become apparent during the course of the following description.

In the drawings we have shown oneembodiment of the invention. In this showing:

FIG. 1- is a central, vertical sectional view of the invention showing the pivotal member locked in position at one limit of its movement;

FIG. 2 is a similar view thereof showing the pivotal member in an intermediate, unlocked position thereof;

FIG. 3 is a similar view showing the pivotal member locked in position at the other limit of its movement;

FIG. 4 is a perspective view thereof to a reduced scale showing the linear-pivotal motion converter in one of its many practical and useful applications;

FIG. 5 is a fragmentary side elevational view to a further reduced scale with portions cut away also showing the application of the converter to an aircraft but slightly modified for positioning against its fire shield;

FIG. 6 is a top plan view to a still further reduced scale of the same application to aircraft; and

FIG. 7 is a side view of the converter'showing a retraction spring mounted thereon.

Referring to the drawings, numeral 10 designates the converter as a whole which comprises a rectangular I box-like housing having opposed sides 11' and 12, an

end 14 having a lower portion cutaway as at 16, an opposing L-shaped end 18, and a wedge shaped shuttle 20 fixed to and mounted on an actuator rod 22 journalled in bearing holes 24, 25 positioned respectively in alignment in the upper portions of the ends 14 and 18.

The rod mounted shuttle 20 has reversible linear movement between the inner faces of the two ends l4, l8 and also between the inner, upper faces 26 and 28 of the outer ends of the legs 30 and 32 respectively of an L-shaped cam 34 which is pivotally mounted in and between the sides of the housing walls 11 and 12 as by a pin 36. The member 38 which is to be reversibly pivoted is suitably mounted in the heel 40 of the L-shaped cam 34.

The outer ends of the legs 30 and 32 of the cam 34 are bifurcated as at 42 and 44 respectively to permit sliding movement of the actuator rod 22 therebetween but not the shuttle 20 which transmits its linear motion to the pivotal cam 34. The juncture of the legs 30 and 32 is recessed as at 46 to enable the cam to provide constant support for the shuttle andthe rod when the hole 25 is not utilized as will be described inconnection with a slight modification of the invention. It is to be noted that the passing of the actuator rod 22 through the bifurcations 42 and 44 of the cam legs eliminates any side load forces.

As shown in FIGS. 1-3 inclusive, the shorter leg of the end wall 18 has an end face 48 and an upper face 50 which function respectively as stops or seating faces for the cam heel 40 and the cam bifurcations 42 when the pivotal member 38 is in the vertical and horizontal positions and are locked against such seating surfaces by the wedge shaped shuttle 20.

A feature of the invention resides in the fact that the distance the shuttle 20 moves between the end walls 14 and 18 is not critical because cam 34 is locked in either limit of its pivotal movement as long as the shuttle engages any part of the upper surfaces 26 (FIG. 1) or the upper surfaces 28 (FIG. 3) of the bifurcated legs of the cam. Also, while the converter is shown as converting the linear movement of the shuttle 20 into a pivotal movement of the member 38, the amount of arc may be increased or decreased as desired by changing the relative angle between the seating surfaces or the contacting faces or their thicknesses.

The operation of the converter is believed to be readily apparent. Linear movement of the shuttle 20 v with the actuation rod 22 to the right from one limit of movement position of the pivotal member 38 (FIG. 1) is effected by means of a suitable servo motor M. As the shuttle 20 moves off of the locking surface 26 of the bifurcated legs 30 to the intermediate unlocked position (FIG. 2), it engages the faces 28 of the bifurcated legs 32 to initiate pivotal movement of the member 38.

As the shuttle 20 moves further to the right, it effects further clockwise pivoting of the cam 34 to the position of FIG. 3 where'the shuttle engages and moves over the face 28 of the bifurcated legs 32 to lock the cam and its member 38 in vertical position against the seating face 48 by the cam heel 40. When it is desired to reverse the 90 pivotal movement of the member 38, the servo motor is reversely actuated and the identical series of movements, etc. described above is reversed to regain the position of FIG. 1.

As will be appreciated, the linear-pivotal converter has many applications of which one is disclosed in FIGS. 4-7 inclusive. This relates to its installation in an aircraft, actual or a model thereof, designated generally by numeral 52. Three converters 10 are employed to actuate the retractable landing gear, one for the nose gear and one for each of the gear positioned in the aircrafts wings. A single servo motor M which provides a reversible rotation of a disc 54 to which the actuator rods 22 of each converter 10 are connected as at 55 by slightly'flexible shafts 56 and couplings 58 to accommodate the disc movement, is positioned in alignment with each converter. In this application, the pivotable members 38 of each converter have a landing wheel 60 mounted on the outer ends thereof.

FIGS. 4, 5 and 7 show the pivotal member 38 with its landing wheel 60 locked in the vertical, extended position. To offset the weight of the landing wheel during its retraction, a heavy coil spring 62 may be secured to the converter housing wall 11 as at 64, partially wound about the cam pivot pin 36 and secured to a collar 66 fixed to the pin (FIG. 7). Where the converter to which the nose wheel 60 is mounted is positioned against an aircraft firewall 68 (FIG. 5), the end of the actuator rod 22 projecting from the left of the converter (position of FIG. 1) may be cut off and proper guidance of the spindle 20 and rod 22 obtained by suitably securing a top cover 70 to the converter housing.

It is to be understood that the forms of our invention herewith shown and described are to be taken as pre ferred examples of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departure from the spirit of the invention or the scope of the subjoined claims.

What is claimed is: I

l. A linear-pivotal motion converter comprising, in combination, a housing having side and end walls; one of said walls being L-shaped and having stops for the legs of a cam; an L-shaped cam rotatably mounted in the side walls of said housing; a member fixed to said cam for pivotal movement therewith; an actuator rod mounted for reversible linear motion in said end walls adjacent said cam; a shuttle fixed to said actuator rod and positioned between the legs of said cam for alternate engagement therewith; and means for effecting reversible linear movement of said rod and said shuttle to engage the legs of said cam and effect pivotal movement thereof and of said member.

2. The combination recited in claim 1 wherein said shuttle moves one of said cam legs against one of said stops in either limit of pivotal movement to lock said cam and said member against movement.

3. The combination recited in claim 2 wherein said cam legs are unlocked when said shuttle is in a position intermediate the end walls of said housing.

4. The combination recited in claim 1 wherein said cam legs are bifurcated to accommodate said actuator rod.

5. The combination recited in claim 1 wherein said housing is mounted on an aircraft, said member pivots downwardly to a substantially vertical position, and a wheel is mounted on the outer end of said member to function as anaircraft landing wheel.

6. The combination recited in claim 5 wherein a spring connects said cam and said housing to assist in the reverse pivoting of said landing wheel to a position within the aircraft.

7. The combination recited in claim 1 wherein said housing is provided with a cover to act as a guide for said shuttle.

8. The combination recited in claim 2 wherein said housing is mounted on an aircraft, said member pivots downwardly to a substantially vertical position, and a wheel is mounted on the outer end of said member to function as an aircraft landing wheel.

9. The combination recited in claim 8 wherein a spring connects said cam and said housing to assist in the reverse pivoting of said landing wheel to a position within the aircraft.

10. The combination recited in claim 2 wherein said housing is provide with a cover to act as a guide for said shuttle. 

1. A linear-pivotal motion converter comprising, in combination, a housing having side and end walls; one of said walls being Lshaped and having stops for the legs of a cam; an L-shaped cam rotatably mounted in the side walls of said housing; a member fixed to said cam for pivotal movement therewith; an actuator rod mounted for reversible linear motion in said end walls adjacent said cam; a shuttle fixed to said actuator rod and positioned between the legs of said cam for alternate engagement therewith; and means for effecting reversible linear movement of said rod and said shuttle to engage the legs of said cam and effect pivotal movement thereof and of said member.
 2. The combination recited in claim 1 wherein said shuttle moves one of said cam legs against one of said stops in either limit of pivotal movement to lock said cam and said member against movement.
 3. The combination recited in claim 2 wherein said cam legs are unlocked when said shuttle is in a position intermediate the end walls of said housing.
 4. The combination recited in claim 1 wherein said cam legs are bifurcated to accommodate said actuator rod.
 5. The combination recited in claim 1 wherein said housing is mounted on an aircraft, said member pivots downwardly to a substantially vertical position, and a wheel is mounted on the outer end of said member to function as an aircraft landing wheel.
 6. The combination recited in claim 5 wherein a spring connects said cam and said housing to assist in the reverse pivoting of said landing wheel to a position within the aircraft.
 7. The combination recited in claim 1 wherein said housing is provided with a cover to act as a guide for said shuttle.
 8. The combination recited in claim 2 wherein said housing is mounted on an aircraft, said member pivots downwardly to a substantially vertical position, and a wheel is mounted on the outer end of said member to function as an aircraft landing wheel.
 9. The combination recited in claim 8 wherein a spring connects said cam and said housing to assist in the reverse pivoting of said landing wheel to a position within the aircraft.
 10. The combination recited in claim 2 wherein said housing is provide with a cover to act as a guide for said shuttle. 